Apparatuses and methods for making seal rings for caps, and thus obtained seal rings

Abstract

An apparatus for forming an object from plastics material includes a forming arrangement having a recess for forming an edge zone of the object, the recess extending around an internal region of the forming arrangement and a conduit cooperating with a piston device to supply the plastics material to the recess, the conduit leading into the internal region into a position contiguous with the recess.

1 - 142 . (canceled) 
     
     
         143 . Apparatus for forming an object from plastics material, said apparatus comprising:
 a molding chamber having at least a chamber portion of annular shape;   a compression-molding arrangement for compression-molding plastics material inside said molding chamber;   an arranging device for arranging at least two doses of said plastics material inside said annular chamber portion such that said at least two doses are separated from one another, said compression-molding arrangement being configured for compression-molding said at least two doses such as to join said two doses to one another;   wherein said compression-molding arrangement comprises at least a movable molding device of annular shape that bounds said molding chamber; and   wherein said compression-molding arrangement comprises at least a support configured for supporting a closing element for containers, said arranging device being configured for arranging said at least two doses on a wall of said closing element supported by said support, said compression-molding arrangement being configured for compression-molding said at least two doses on said wall.   
     
     
         144 . Apparatus according to  claim 143 , wherein said arranging device is configured for simultaneously arranging at least three doses of said plastics material that are not aligned together. 
     
     
         145 . Apparatus according to  claim 143 , wherein said arranging device comprises at least two pushing elements for depositing said at least two doses on a resting surface, said compression-molding arrangement comprising a molding tool that is movable to said resting surface, said molding tool and said resting surface being able to take on an operating configuration wherein they cooperate to define said molding chamber. 
     
     
         146 . Apparatus according to  claim 145 , wherein said molding tool has at least a molding member that is movable for being able to compress the plastics material and which has one at least partially annular shape. 
     
     
         147 . Apparatus according to  claim 143 , and further comprising an extruding device for extruding the plastics material through at least two extruding outlets, said arranging device comprising at least two separating tools configured for separating each of said at least two doses from the plastics material exiting each of said at least two extruding outlets, said at least two separating tools being configured for retaining and transferring said doses from said extruding outlets to a dose release zone. 
     
     
         148 . Apparatus according to  claim 147 , wherein said at least two separating tools are movable for simultaneously passing in front of said at least two extruding outlets so as to separate and to retain said at least two doses. 
     
     
         149 . Apparatus according to  claim 148 , wherein each of said at least two separating tools has a concave surface with the concavity facing forward in an advancing direction of said at least two separating tools. 
     
     
         150 . Apparatus according to  claim 148 , wherein each of said at least two separating tools comprises a detaching arrangement for detaching said at least two doses from said at least two separating tools that retain said at least two doses. 
     
     
         151 . Apparatus according to  claim 143 , wherein said compression-molding arrangement comprises at least a compression punch having at least an internal member that internally bounds said annular chamber portion and defines an annular obstructing limit of the plastics material during said compression molding.